A rotation regulating device for regulating the rotation of a rotating ring by contacting and stopping the rotating ring is disclosed, for example, in Japanese Unexamined Patent Publication No. 2010-49153 (literature 1). The rotation regulating device disclosed in this literature 1 is used in a lens barrel and includes a rotating ring, a holder rotatably holding the rotating ring and a rotation regulator held on the holder and formed of an elastic body for regulating the rotation of the rotating ring by contacting and stopping the rotating ring. The rotation regulator is held on two shafts formed at a distance from each other on the holder. The rotating ring is contacted and stopped by one circumferential end surface of the rotation regulator in rotating the rotating ring toward one side and the rotating ring is contacted and stopped by the other circumferential end surface of the rotation regulator in rotating the rotating ring toward the other side, whereby the rotation of the rotating ring is regulated.
However, since the rotation regulator is held on the two shafts formed at a distance from each other in the circumferential direction of the rotating ring in the literature 1, the rotation regulator is easily displaced from a set position relative to the rotating ring due to the position of each of the two shafts and dimensional manufacturing errors such as an interval between the two shafts and it is difficult to arrange the rotation regulator at the set position relative to the rotating ring.
Since the rotation regulator is held on the two shafts formed at a distance from each other in the circumferential direction of the rotating ring, a length (width) of the rotation regulator in the circumferential direction is long. As a result, the dimensional accuracy of the rotation regulator formed of the elastic device is reduced. In addition, an arrangement space for the rotation regulator becomes larger and an arrangement space for another member becomes narrower.